Head lettuce and other harvested perishable food products are normally packed into cartons at a field site. The cartons are then closed and stacked on pallets, suitably disposed on the flatbed of a truck. The palletized cartons are then delivered to a cooling facility, including a standard pre-vacuum cooling tube and a cold storage building, to maintain the product at a predetermined low temperature (e.g., 34.degree. F.) for preservation purposes.
It is common practice to utilize a lift truck to move the palletized cartons into the cold storage building whereat they are deposited for storage purposes. Each palletized carton stack usually constitutes six layers of cartons, with all of the palletized carton stacks being deposited directly on the cement floor of the building. Thus, substantial storage space is lost above the six-layer heights of the palletized carton stacks.
U.S. Pat. Nos. 4,640,657 and 4,900,219 disclose typical carton handling and loading systems.